Conventional control valves in process plants do not have smart positioners or other self-provided feedback mechanisms for allowing a user to tell how well such valves are performing. This also means that the cost of conventional control valves is low compared to smart valves, so that conventional valves can be expected to continue to account for more than half the total valve demand this year.
However, unchecked and undetected deterioration in a conventional control valve can have significant impact on process control, and in extreme cases, may lead to unscheduled plant shutdown. Considering that there are currently no online or real-time performance monitoring diagnostics tools for such conventional control valves available, while the usage of conventional control valves in process plants worldwide will continue to be high, this can be seen to be a problem of substantial scale.